Venus, the second planet from the Sun, is the hottest world in the solar system.
Because of Venus' extremely thick atmosphere, the planet suffers from a runaway
Greenhouse effect. Energy from the Sun passes through the atmosphere to the
planet's surface, where it is absorbed and radiated at longer wavelengths as infrared.
Venus' atmosphere traps these longer wavelengths so they cannot escape into
space. The trapped energy builds up, so the planet grows hotter and hotter.

With a surface temperature of almost 480 °C (900 °C), this
place is hot enough to melt lead. Because of Venus' heavy atmosphere, the
planet's surface pressure is very high. Pressure is defined as the weight of the atmosphere
pressing down on you per unit area. On Earth, we don't notice the air pressure
at all. The thick atmosphere on Venus would make it difficult to see objects
very far away from you. Since carbon dioxide is poisonous to humans, you would
not be able to breathe on Venus.

Although the gravity on Venus is about the same as on Earth, the weight of
the atmosphere would crush you. There are always thunderstorms somewhere
on the planet, and lightning flashes about 25 times every second somewhere in
Venus' atmosphere. The atmospheric pressure at the surface of Venus
is about 90 times that of Earth's (90 atm). This atmosphere consists
mainly of carbon dioxide, which is a gas that is not breathable. In addition,
the clouds of Venus contain drops of sulfuric acid, a poisonous chemical.